Well-drilling tool

ABSTRACT

A well-drilling tool for rotary drilling comprising a main bit and a set of radially expansible and contractable under-reamers actuatable by weight applied through the drill pipe string.

contractable pplied through the drill [5 6] References Cited UNITED STATES PATENTS 1,997,436 4/1935 2,719,701 10/1955 Kammerer,.1r..... 2,754,090 7/1956 Kammerer....................

Primary Examiner-James A. Le

Atr0rneyR. Werlin ABSTRACT: A well-drillin a main bit and a set of ra undern, Tex.

5329 Sturbridge Drive, Housto 77027 [21] AppLNo. 36,810

[22] Filed Cicero C. Brown May 13, 1970 10 Claims, 5 Drawing Figs. [52] [50] FieldofSearch,......................

United States Patent [72] Inventor [45] Patented Jan. 11, 1972 [54] WELL-DRILLING TOOL 5 i yffe W1 7; Z

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WELL-DRILLING TOOL Underreamers are conventionally employed in well drilling to enlarge the well bore diameter drilled by a preceding drill bit. Two types of underrearners are commonly employed. One employs an arrangement in which the underrearners are fixedly mounted on their support body to project at a predetermined angle or distance relative to the axis of the body. In another conventional construction, the underrearners are pivotally mounted for radial extension and retraction and are actuatable by hydraulic pressure applied through the drill string.

The present invention is directed to a form of drilling tool which combines a main or pilot bit with a set of pivotally mounted underreamers which are actuatable is response to weight applied to the actuating mechanism by the drill string to effect extension and retraction of the underrearners.

The construction contemplated in accordance with this invention includes a tubular outer member carrying on its lower end a main or pilot bit and a plurality of underrearners pivotally mounted to the body above the main bit for radial extension and retraction. An inner tubular member is connectable to a drill pipe string and extends into the bore of the outer member and a splined connection is provided between the members to form a nonrotative, telescopic connection therebetween.

The underrearners are operably connected by a crank and crosshead pin connection to a plunger which is secured to a setting sleeve which is, in turn, connected to the inner tubular member by means through which application of weight through the drill pipe string will extend the underrearners and relief of weight by raising of the pipe string will retract the underreamers. The setting sleeve also carries anchor elements operable by the downward movement of the pipe string to first extend the underrearners and then to lock the underrearners in their extended position; and by the upward movement of the pipe string to first release the anchor elements and then retract the underrearners.

The described arrangement assures that the underrearners will be securely locked in their extended relation which drilling ahead but will be readily retractible in response to lift on the drill pipe when it is desired to raise the drill string out of the well bore.

Other and more specific objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates a useful embodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal sectional view of the drilling tool, showing the parts in the underreamer-retracted position;

FIG. 2 is a view similar to FIG. 1 showing the parts in the underreamer-extended position;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 1; and

FIGS. 4 and 5 are cross-sectional views taken respectively on lines 44 and 5-5 of FIG. 2.

Referring to the drawing, the tool comprises a tubular outer member, designated generally by the letter A, and a tubular inner member, designated generally by the letter B having telescopic nonrotative connection to outer member A.

Member A comprises a tubular housing having a bore 11 and carrying at its lower end a collar 12 provided at its lower end with an internally threaded socket 13 adapted to threadedly receive the hollow shank 14 of a main or pilot bit 15, which may be of any well-known design, a roller-type bit being illustrated by way of example. Housing 10 is provided above collar 12 with a plurality of angularly spaced-apart, elongate radial slots 17 in which are pivotally mounted underrearners, each designated generally by the numeral 18, to be described more fully hereinafter.

Inner tubular member B comprises a tubular body 20 having an axial bore 21 and provided at its upper end with an internally threaded box 22 by means of which the tool may be connected to the lower end of a drill pipe string P. Body 20 is provided with a plurality of angularly spaced, longitudinally extending, dovetail male splines 23 adapted to be received in correspondingly shaped female spline slots 24 formed in the wall of bore 11 and opening to the upper end of housing 10 (See FIG. 4). Splines 23 and spline slots 24 cooperate to provide a nonrotative telescoping connection between inner and outer members A and B. The wall of bore 11 below slots 24 is provided with an annular locking recess 25, the function of which will appear subsequently.

The portion of body 20 inwardly of splines 23 is substantially reduced in external diameter to provide the extension 26 and to thereby define a substantial annular space 27 between extension 26 and the wall of bore I1. An annular enlargement 28 is formed on the exterior of extension 26 at a point between its inner end and its juncture with the larger diameter portion of body 20, the ends of the enlargement defining bevelled upper and lower shoulders 29 and 30 respectively.

A setting sleeve 31 is slidably disposed in space 27 concentrically between extension 26 and housing 10. An abutment ring 32 is mounted in the upper end of sleeve 31 to project inwardly therefrom into overlying relation to shoulder 29 serving thereby to limit downward movement of sleeve 31 relative to extension 26. Sleeve 31 is provided intennediate its upper and lower ends with a plurality of angularly spaced, generally rectangular openings 33 through the wall thereof in which are mounted correspondingly shaped latch dogs 34 whose radial thickness is somewhat greater than the wall thickness of the portion of sleeve 31 which extends above openings 33 which is made somewhat greater in internal diameter than the lower end portion 35 of sleeve 31 below openings 33. Thus, when dogs 34 are in their inwardly retracted position (FIG. 1), the inner ends of the dogs will project inwardly from openings 33 to define shoulders 36 abuttable by shoulders 30 of enlargement 28. When sleeve 31 is moved downwardly relative to casing 10 to a position placing dogs 34 in registration with latch recess 25 (FIG. 2) dogs 34 will be projectable into the recess to allow enlargement 28 to move downwardly behind the dogs and thus project and hold them in locking engagement with recess 25, to thereby lock sleeve 31 against axial movement so long as enlargement 28 remains in the locking position behind dogs 34.

Lower end portion 35 of the setting sleeve is secured to the annular head 37 of a tubular plunger 38 having an axial bore 38a. The lower end of plunger 38 extends slidably and in sealed relation through a central opening 39 in an upwardly tapering conical cap mounted to the upper end of collar 12.

Each of the underrearners comprises a cutter arm 40 and a crank arm 41 extending at an angle to the cutter arm. A pivot pin 42 extends transversely through the crank arm and is journaled in the walls of slot 17 (FIG. 5). The free end of the cutter arm carries an inwardly extending cutter shaft 43 on which is rotatably mounted a frustoconical cutter 44 of a generally conventional design, the details of which do not form a part of this invention. Crank arm 41 is formed with an extension 45, the free end of which carries an inwardly projecting crosshead pin 46 positioned in a crosshead slot 47 provided in a related side portion of plunger 38. With this arrangement it will be seen that the movement of plunger 38 downwardly will act on crosshead pins 46 and thence through extensions 45 and crank arm 41 to rotate the underrearners outwardly while reverse movement of the plunger will act to retract the underrearners.

A plurality of jets 50 are mounted in the walls of cap 19 and directed so as to discharge fluid upwardly and outwardly at an angle selected to cause the fluid to strike the extended teeth of cutters 44 to wash cuttings therefrom, as well as to strike the wall of the well bore at points immediately in advance of the cutters to apply a softening or washing action thereon which will aid the underreamer cutters in more efficiently performing their function.

In operation, the tool attached to drill pipe P will be run into a preexisting well bore, such as the usual surface hole, the

setting sleeve and the underrearners being in their retracted positions illustrated in FIG. 1. The engagement of abutment ring 32 on shoulder 29 will serve to hold outer member A suspended from inner member B with the several parts in the retracted positions shown.

When bit lands on bottom, pipe string P will be lowered to apply weight through shoulder 30 to shoulders 36 on dogs 34 thereby pushing sleeve 31- downwardly. This downward movement of the sleeve will be transmitted through plunger 38 to extend the underreamers, this movement continuing until latch dogs 34 move opposite recess 25 whereupon the dogs are free to move outwardly into recess 25 allowing enlargement 28 to move behind the dogs and lock them into the latch recess and thereby lock the underreamers in their fully extended position (FIG. 2). The length of spline slots 24 will be selected to cause male splines 23 to bottom therein when relative downward travel of inner member B has enabled the underreamers and the several latch parts to reach their fully actuated positions.

When the parts are in the positions shown in FIG. 2 the drill pipe string may be rotated, rotating the pilot bit and the underreamers. Drilling fluid pumped under pressure through the drill string will flow through bores 21 and 38 into the bores of collar 12 and bit shank 14. A part of this fluid will be discharged through the usual slush ports 49 in bit 15 and part will be ejected through jets 50 as the drilling proceeds.

When desired to retract the underreamers, it is only necessary to pick up slightly on the drill string. This will lift inner member B sufficiently to raise enlargement 28 sufficiently to clear dogs 34 and allow them to retract from recess 25. As soon as shoulder 29 strikes abutment ring 32 the upward pull will be transmitted to setting sleeve 31 which will then pull upwardly on plunger 38 and produce retraction of the underreamers, the parts thus being retumed'to the positions shown in FIG. 1.

It will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

l. A drilling tool comprising:

a. inner and outer tubular members connected for telescopic, nonrotative movements, said outer member having an annular locking recess in the inner wall thereof;

b. means for connecting the upper end of the inner member to a pipe string;

c. a drill bit carried by the lower end of the outer member;

d. a plurality of underreamers pivotally mounted to the outer member above the drill bit for radial extension and retraction relative to said outer member;

. a sleeve member concentrically disposed between said tubular members connected to said underreamers and operable to effect said extension and retraction thereof respectively in response to movement of said sleeve member between downward and upward positions relative to said outer member; means forming a slidable connection between said sleeve member and said inner tubular member arranged to limit the movement of the sleeve member between said positions;

g. anchor elements mounted in openings in the wall of said sleeve member for radial movement into and out of anchoring engagement with said recess; and

h. means carried by said inner member cooperating with said anchor elements and said sleeve member to produce said movements of the sleeve member between said downward and upward positions whereby to respectively project said anchor elements into said recess and to release said anchor elements for retraction from said recess contemporaneously with said extension and retraction of said underreamers.

2. A drilling tool according to claim 1 including longitudinally extending, cooperating splines in said members form ing the telescopic, nonrotative connection therebetween.

forming said slidable connection comprises; an annular abutment ring mounted on the upper end of said sleeve member to project inwardly over said enlargement.

6. A drilling tool according to claim 1 wherein said anchor elements have a radial thickness slightly greater than that of the wall of said sleeve member above said openings whereby when in radially retracted position to define shoulders thrustingly engageable by said inner member.

7. A drilling tool, comprising:

a. an outer tubular member;

b. an inner tubular member connectable to a drill pipe string and extending into the bore of said outer member;

0. means connecting said members for telescopic, nonrotative movement;

d. a drill bit carried by the lower end of the outer member;

e. a plurality of underreamers pivotally mounted to the outer member above the drill bit for radial expansion and retraction; and

f. means pivotally connecting said inner member to said underreamers responsive to longitudinal movement of said inner member relative to said outer member between a downward position operable to sequentially extend said underreamers and to lock them in the extended position and an upward position operable to sequentially release and retract said underreamers.

8. A drilling tool comprising:

a. inner and outer tubular members connected for telescopic, nonrotative movement, said outer member having an annular locking recess in the inner wall thereof;

means for connecting the upper end of the inner member to a pipe string;

c. a bit-receiving collar carried by the lower end of the outer member;

d. an upwardly tapering conical cap for the upper end of said collar having a central opening;

e. a plurality of underreamers pivotally mounted to the outer member above said collar for radial extension and retraction;

f. a sleeve member slidably disposed concentrically between said tubular members;

g. a tubular plunger having one end secured to said sleeve member and the other end extending slidably through the opening in said cap;

h. means connecting said plunger means to said underreamers operable to effect said extension and retraction thereof in response respectively to movement of said sleeve member between downward and upward positions relative to said outer member;

. means forming a slidable connection between said sleeve member and said inner tubular member to limit the movement of of the sleeve member between said positions;

j. a plurality of angularly spaced openings through the wall of said sleeve member;

k. anchor elements mounted in said openings for radial movement into and out of anchoring engagement with said recess; and

l. means carried by said inner member cooperating with said anchor elements and said sleeve member to produce said movements of the sleeve member between said downward and upward positions whereby to respectively project into and release from said recess said anchor elements while contemporaneously extending and retracting said underreamers.

a. angular crank arms carrying said underreamers; b. crosshead slots in the exterior of said plunger; and c. crosshead pins mounted on said crank arms and slidably disposed in said slots.

l #0 k k I. 

1. A drilling tool comprising: a. inner and outer tubular members connected for telescopic, nonrotative movements, said outer member having an annular locking recess in the inner wall thereof; b. means for connecting the upper end of the inner member to a pipe string; c. a drill bit carried by the lower end of the outer member; d. a plurality of underreamers pivotally mounted to the outer member above the drill bit for radial extension and retraction relative to said outer member; e. a sleeve member concentrically disposed between said tubular members connected to said underreamers and operable to effect said extension and retraction thereof respectively in response to movement of said sleeve member between downward and upward positions relative to said outer member; f. means forming a slidable connection between said sleeve member and said inner tubulaR member arranged to limit the movement of the sleeve member between said positions; g. anchor elements mounted in openings in the wall of said sleeve member for radial movement into and out of anchoring engagement with said recess; and h. means carried by said inner member cooperating with said anchor elements and said sleeve member to produce said movements of the sleeve member between said downward and upward positions whereby to respectively project said anchor elements into said recess and to release said anchor elements for retraction from said recess contemporaneously with said extension and retraction of said underreamers.
 2. A drilling tool according to claim 1 including longitudinally extending, cooperating splines in said members forming the telescopic, nonrotative connection therebetween.
 3. A drilling tool according to claim 1 wherein the means connecting said sleeve member to said underreamers includes: a. plunger means secured to said sleeve member; and b. crank arms operably connecting said underreamers to said plunger means.
 4. A drilling tool according to claim 1 wherein said last-mentioned means comprises an annular enlargement on the exterior of said inner member spaced from the inner end thereof.
 5. A drilling tool according to claim 4 wherein said means forming said slidable connection comprises; an annular abutment ring mounted on the upper end of said sleeve member to project inwardly over said enlargement.
 6. A drilling tool according to claim 1 wherein said anchor elements have a radial thickness slightly greater than that of the wall of said sleeve member above said openings whereby when in radially retracted position to define shoulders thrustingly engageable by said inner member.
 7. A drilling tool, comprising: a. an outer tubular member; b. an inner tubular member connectable to a drill pipe string and extending into the bore of said outer member; c. means connecting said members for telescopic, nonrotative movement; d. a drill bit carried by the lower end of the outer member; e. a plurality of underreamers pivotally mounted to the outer member above the drill bit for radial expansion and retraction; and f. means pivotally connecting said inner member to said underreamers responsive to longitudinal movement of said inner member relative to said outer member between a downward position operable to sequentially extend said underreamers and to lock them in the extended position and an upward position operable to sequentially release and retract said underreamers.
 8. A drilling tool comprising: a. inner and outer tubular members connected for telescopic, nonrotative movement, said outer member having an annular locking recess in the inner wall thereof; b. means for connecting the upper end of the inner member to a pipe string; c. a bit-receiving collar carried by the lower end of the outer member; d. an upwardly tapering conical cap for the upper end of said collar having a central opening; e. a plurality of underreamers pivotally mounted to the outer member above said collar for radial extension and retraction; f. a sleeve member slidably disposed concentrically between said tubular members; g. a tubular plunger having one end secured to said sleeve member and the other end extending slidably through the opening in said cap; h. means connecting said plunger means to said underreamers operable to effect said extension and retraction thereof in response respectively to movement of said sleeve member between downward and upward positions relative to said outer member; i. means forming a slidable connection between said sleeve member and said inner tubular member to limit the movement of of the sleeve member between said positions; j. a plurality of angularly spaced openings through the wall of said sleeve member; k. anchor elements mounted in said openings for radial movement into and out of anchoring engagement with said recess; and l. means carried by said inner member cooperating with said anchor elements and said sleeve member to produce said movements of the sleeve member between said downward and upward positions whereby to respectively project into and release from said recess said anchor elements while contemporaneously extending and retracting said underreamers.
 9. In a drilling tool according to claim 8, a plurality of fluid jets mounted through the wall of said cap for directing fluid from the interior of the cap toward said underreamers.
 10. A drilling tool according to claim 8 wherein said means connecting said plunger means to said underreamers comprises: a. angular crank arms carrying said underreamers; b. crosshead slots in the exterior of said plunger; and c. crosshead pins mounted on said crank arms and slidably disposed in said slots. 